The Swingarm and rear diff are from an R1150rs.
The RS is BMW Sports Tourer, i've gone for a 2000 model, which has higher final drive ratio to the R65.
Quite honestly when i thought about the project i didn't really make a plan for 'what if', all i thought was a little revvy R65 on 17" cast wheels and R1 forks would be a fantastic ride, and am still really excited to get it going!!
the mock test of the swingarm shows the RS to be a thinner bike to the R65 by 10mm or so
The Initial plan is to knock something up on the lathe to secure it in place.
Luckily BMW never changed the sizes of their swingarm locating bolts so thats one less thing to work out!!
Going off the picture it all looks to be working out so far, but i've still to put wheels on it!!